Kenneth Kishida, Ph.D. Wake Forest University School of Medicine

时间: 2017-06-19 13:00 - 15:00

地点: Room 1113, Wang Kezhen Building

My lab is interested in discovering how the human brain gives rise to conscious behavior and willful decision-making. We approach these problems from a neuro-computational perspective wherein we aim to determine the neurobiological processes that act to process information and guide behavior in humans. To do this, we use computationally framed decision-making games paired with invasive and non-invasive brain measurements in healthy humans and humans with brain disorders. In this seminar, I will describe new technology recently developed by my team that allow us to simultaneously measure dopamine and serotonin fluctuations in the human brain with sub-second temporal resolution. I will also discuss new results that begin to show how dopamine and serotonin coordinate in real-time in the human brain to control behavior and influence decision-making.

We have made simultaneous real-time (10Hz) measurements of dopamine and serotonin fluctuations in the striatum of humans engaged in continuous decision-making tasks. These measurements are made using fast scan cyclic voltammetry on carbon fiber microelectrodes acutely implanted in the striatum of patients undergoing deep brain stimulation electrode implantation for the treatment of Parkinson's disease symptoms. To analyze these data penalized regression and a substantial calibration data set were used to train models for estimating dopamine and serotonin levels from non-background subtracted voltammograms. I will show that this approach produces models that: (1) accurately track dopamine and serotonin fluctuations for long periods (>30min), (2) discriminate dopamine, serotonin, and pH fluctuations, while (3) overcoming the effects of electrode fouling and background drift that have plagued previous approaches. I will also show that sub-second dopamine and serotonin fluctuations in the human brain encode changes in expectations and evaluative feedback; further, neurochemical fluctuations in one trial are predictive of actions in the next trial. Overall, I hope to convey how this new technology promises new opportunities for investigating the role neuromodulators play in computational processes supporting conscious experience and willful choice directly in the human brain.